In developing fabric care compositions, the primary focus is on incorporation of the actives into the products and delivery of the actives onto the fabrics such that the treated fabrics exhibit the desired fabric care benefits. Through-the-rinse applications pose special challenges in the area of effective deposition from the rinse medium to the fabrics. In some cases, it is found that fabric care actives having cationic moieties and long alkyl chains (e.g., alkyl quats) are very sensitive to certain detergent components (e.g., anionic surfactant) that are carried over from the wash cycle into the rinse cycle. It is hypothesized that the anionic detergent components may interact with the cationic fabric care actives, forming cationic-anionic complexes that may precipitate out of the rinse medium and/or neutralize the softening actives. The former reduces deposition onto fabrics and the latter reduces effectiveness of the fabric care actives.
Additionally, prior fabric care compositions typically contain actives that require a low pH environment to be functional and stable. However, such compositions also contain other important actives, such as certain perfume microcapsule materials, silicone surfactants, quaternary ammonium compounds, that may undergo changes or become unstable and/or non-functional at low pH. Therefore, active ingredients that are stable and function in a neutral or higher pH environment are desirable in formulating fabric care compositions.
Fabric care compositions comprising nonionic softening actives have been disclosed. Examples of nonionic fabric softening actives include fatty acid partial esters of polyhydric alcohols and anhydrides, especially sucrose esters, sorbitan esters, glycerol esters and polyglycerol esters. To ensure effective deposition onto fabrics, these nonionic fabric care actives may be used in combination with other co-actives or deposition agents. Exemplary compositions comprising nonionic fabric softening actives and/or deposition agents are disclosed in U.S. Pat. No. 4,162,984; U.S. Pat. No. 4,237,016; U.S. Pat. No. 4,439,330; U.S. Pat. No. 5,476,599; U.S. Pat. No. 5,559,088; U.S. Pat. No. 5,830,835; U.S. Pat. No. 6,165,953; U.S. Pat. No. 6,277,796.
Furthermore, it is well recognized that consumer acceptance of a fabric care product is determined not only by the softening/static control performance of the product but also by the fragrance aesthetics it provides. It is also desired by consumers for treated fabrics to maintain over time the pleasing fragrance imparted by the treatment product.
However, the amount of perfume carried over from a laundering operation onto fabrics is often marginal and does not last long on the treated fabrics. The fragrance materials in the treatment product either fail to deposit onto the fabrics or are washed away. Additional amount of fragrance materials are released from the fabrics and lost through the dryer vent during the heat drying cycle. Each of these intrusions not only results in a diminished level of perfume raw materials, but also a loss of fragrance “balance” or aesthetic character. Since fragrance materials are expensive, the inefficient use in the product or in the delivery to fabrics results in a high cost to both the consumers and the product manufacturers.
Various fragrance materials have been found to react with amine-containing compounds and the resulting products have shown to provide long lasting perfume release from the treated fabrics. It has also been found that these fragrance materials and amine-containing compounds can be separately added to the product and still provide long lasting fragrance benefit. The amine-assisted perfume delivery systems are disclosed in, for example, WO 00/02991; WO 00/02981; WO 00/02982; WO 00/02987; U.S. Pat. No. 6,858,575; U.S. Pat. No. 6,916,769; US 2003/0,134,772; US 2005/0,123,497.
There is a continuing need to improve fabric care compositions to deliver efficient deposition and enhanced fabric care benefits. Further, there is a continuing need for more efficient and effective perfume delivery in fabric care products. There is also a continuing need for improving the perfume longevity as well as perfume balance on the treated fabrics. In addition, there is a continuing need to have a fabric care composition that is stable and function at neutral pH.